package test.java.org.pzone.crypto;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.nio.ByteBuffer;

public class ComFn {
	public static String bytesToHexString(byte[] src, int len){
        StringBuilder stringBuilder = new StringBuilder("");
        if (src == null || len <= 0) {
            return null;
        }
        for (int i = 0; i < len; i++) {
            int v = src[i] & 0xFF;
            String hv = Integer.toHexString(v).toUpperCase();
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv);
        }
        return stringBuilder.toString();
    }
	
	public static byte[] hexStr2Byte(String hex) {
	    ByteBuffer bf = ByteBuffer.allocate(hex.length() / 3);
	    for (int i = 0; i<hex.length(); i++) {
	        String hexStr = hex.charAt(i++) + "";
	        hexStr += hex.charAt(i++);
	        hexStr += hex.charAt(i);
	        byte b = (byte) Integer.parseInt(hexStr.trim(), 16);
	        bf.put(b);
	    }
	    return bf.array();
	}
	
	/**
     * 把一个文件转化为byte字节数组。
     *
     * @return
     */
    public byte[] fileConvertToByteArray(String src_file) {
        byte[] data = null;
 
        try {
            FileInputStream fis = new FileInputStream(new File(src_file));
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
 
            int len;
            byte[] buffer = new byte[1024];
            while ((len = fis.read(buffer)) != -1) {
                baos.write(buffer, 0, len);
            }
 
            data = baos.toByteArray();
 
            fis.close();
            baos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        return data;
    }
}